1. Field of the Invention
The present invention relates to electromagnetic driving devices, particularly to a current supply device for an electromagnetic driving mechanism for opening and closing the shutter blades of a camera.
2. Description of the Prior Art
Various types of the electromagnetic driving devices for opening and closing shutter blades are known, with the device having the simplest construction being the meter type electromagnetic driving source is known. Namely, in the magnetic field of the stator consisting of a permanent magnet such that the exciting current is supplied to the coil so as to rotate the coil, thereby making use of the coil torque to drive the shutter blades.
Until now, the current supply to the moving coil of the electromagnetic driving device has been transmitted through the cntact between the current supply brush and the slide surface provided on the rotation shaft. The brush is in contact with the slide surface only at one point, so that due to oxidation of the contact surface contact often becomes inferior, which prevents a reliable current supply such a manner that the operation of the shutter is prevented or making it unstable.